Improvement in oscillating valves for steam-engines



W. HARnw1cK. OSCILLA'IIING-VALY'ES -FOR STEAM-ENGINES.

Patented Aug.,14,1e77.

mulini-ns.

UNITED STATES PATENT OFFICE.

WILLIAM HARDWIGK, OF ERIE, PENNSYLVANIA.

IMPROVEMENT IN OSCILLATING VALVES FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 194,238, dated August 14, 1877; application filed February 26, 1877.

To all whom it may concern Be it known that I, WILLIAM HARDWIGK, of Erie, in the county of Erie and State of Pennsylvania, have invented a new and Improved Oscillating Valve, of which the following is a speciication:

Figure l is a longitudinal section on line y y in Fig. 2. Fig. 2 is a transverse section on line w @a in Fig. 1.

Similar letters of reference indicate correspondin g parts.

My invention relates to oscillating valves for steam-engines; and it consists of two oscilating D-valves, placed in a cylindrical valvechest with their backs together, and connected by a bolt. Y

The valves have equal areas, so that they exactly counterbalanoc each other. One of the valves moves on the ordinary valve-seat, While the other moves on a seat formed in the side of the chest opposite the steam-ports.

In the drawing, A is a cylindrical steamchest, (shown in dotted lines,) and B is an ordinary oscillating valve, that is slotted to receive the squared portion of the rocking shaft a, and is out away at b to receive theenlarged portion c of the said rocking shaft. C is a valve of the same area as the valve B, which is slotted to receive the back of valve B. A tap-bolt, D, passes through the valve (l and shaft a into the back of the valve B, and is provided with a collar, d, which engages the back of the valve C, and holds the said valve out against its seat when the steam-pressure is oi'. The upper end of the bolt is threaded to receive a nut, e, by which the pressure of the valves upon their seats is limited, and is provided with a square head for receiving a wrench.

An aperture, F, stopped by a screw-plug, G, is provided for adjusting the valve without removing the head of the steam-chest.

The advantages claimed for my improvement are, that the valve is perfectly balanced, 

